<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .green {
            background-color: green;
        }

        .orange {
            background-color: orange;
        }

        .clearfix::after {
            content: '';
            display: block;
            clear: both;
        }

        .w150 {
            width: 150px;
            height: 50px;
        }

        .wings main {
            float: left;
            width: 100%;
        }

        .wings .inner {
            margin: 0 150px;
            height: 75px;
        }

        .wings .left {
            float: left;
            margin-left: -100%;
        }

        .wings .right {
            float: left;
            margin-left: -150px;
        }
    </style>
</head>

<body>
    <div class="layout">
        <h4>方法二：双飞翼布局</h4>
        <section class="wings clearfix">
            <main>
                <div class="green inner">

                </div>
            </main>
            <aside class="w150 left orange">
                aside-left
            </aside>
            <aside class="w150 right orange">
                aside-right
            </aside>
        </section>
    </div>
</body>

</html>